The study was conducted by collecting water quality data for the 8-year period from 2009 to 2016 from the Department of Natural Resources and Environment, An Giang province to evaluate the surface water quality in Tien and Hau rivers’ segments belonging to An Giang province. The results showed that surface water of Tien and Hau Rivers were organically polluted and microbial contamination. The water quality parameters including biological oxygen demand (BOD), total suspended solids (TSS) and total coliforms were much higher than the National Technical Standards for Surface Water Quality (QCVN 08-MT:2015/BTNMT). The surface water pollution at evaluating sites has been existed for over eight years. The causes of water pollution could be from wastes generated during agricultural, industrial and service activities that have not been thoroughly treated. The results of surface water quality assessment on Tien and Hau Rivers suggested that the current management practices from the governments of upstream and downstream on water quality are not really effective. The appropriate measures are needed to manage surface water quality based on suitable local and international environmental management tools since these rivers are extremely important water sources for people who their lives heavily relying on water quality of the Mekong river.